Plato's Sophist [560-561]

is not, as in the case of the mere exclusion corresponding to the pure calling by name, a letting disappear, a bringing of what is said to nothing.

If these connections are pursued further, it becomes clear that negation, understood in this way, as possessing a disclosive character, can have, within the concrete uncovering of beings, a purifying function, so that negation itself acquires a productive character. To understand this properly, in all its consequences, and above all in its significance for the structure of the concept, and for conceptuality in general, we must free ourselves from the traditional theory of knowledge and of judgment, from the traditional version of knowledge, judgment, the concept, and the like. Above all, the positive understanding of negation is important for the research that moves primarily and exclusively by exhibiting the matters at issue. Phenomenological research itself accords negation an eminent position: negation as something carried out after a prior acquisition and disclosure of some substantive content. This is what is peculiarly systematic in phenomenology, that, provided it is practiced authentically, phenomenology always involves an antecedent seeing of the matters themselves. What is systematic is not some sort of contrived nexus of concepts, taking its orientation from some construct or system. On the contrary, the systematic is grounded in the previous disclosure of the matters themselves,2 on the basis of which negation then attains the positive accomplishment of making possible the conceptuality of what is seen.

Furthermore, it is only on the basis of this productive negation, which Plato has at least surmised here, even if he has not pursued it in its proper substantive consequences, that we can clarify a difficult problem of logic, a problem residing in the copula of the proposition or judgment: namely, the meaning of the "is" or the "is not" in the propositions "A is B," "A is not B." The meaning of this "not," in the context of judgments about beings, has long caused difficulties for logic, and it has not been properly clarified even now. In the last part of our lectures, about λόγος, following this discussion of the ἔτερον, we will have the opportunity to pursue it more closely. Hegelian logic, obviously in conjunction with Aristotle, gives the concept of negativity a positive significance, but only insofar as negativity is a transitional stage, because the total orientation of this dialectic is directed toward essentially other structures than is the simply disclosive dialectic of the Greeks.

The consideration of the five γένη aimed at the exposition of the ἔτερον and thereby at the possibility of making intelligible μὴ ὄν as ὄν. What now follows grasps this structure of the ἔτερον itself still more precisely, in the

2. AH: Sketch.

Martin Heidegger (GA 19) Plato's Sophist